怎么回产生这个异常的？？

[jacky_cai]

public class Find{
public static void main(String args[]){
String s = "dcdabcddese";
char c[] = new char[s.length() + 1];
int i = 1, r1;

c = s.toCharArray();
r1 = s.indexOf("abcd");

if (r1 != -1)
{
for (; r1<r1+4; ++r1, ++i)
{
c[r1] = (char)i;
}
}

System.out.println(c);
}
}

要求是把“abcd”换成1234 编译可以过 运行有数组越界异常 怎么回事？？

[Camelh]

String s = "dcdabcddese";
char[] c ;
int r1;

c = s.toCharArray();
r1 = s.indexOf("abcd");
if (r1 != -1) {
for (int i = 1; i <= 4; ++r1, ++i) {
c[r1] = (char) (i+'0');
}

}
System.out.println(c);

[foxty]

public class Find{
public static void main(String args[]){
String s = "dcdabcddese";
char c[] = new char[s.length() + 1];
int i = 1, r1;

c = s.toCharArray();
r1 = s.indexOf("abcd");

if (r1 != -1)
{
for (; r1<r1+4; ++r1, ++i) ****你这里的r1是在递增的,所以你的循环会一直进行下去.
{
c[r1] = (char)i;
}
}

System.out.println(c);
}
}


可以实现定义需要循环的次数
int length = r1 + 4;

if (r1 != -1)
{
for (; r1<length; ++r1, ++i)
{
c[r1] = (char)i;
}
}

[langya333]

你的for循环中:
for (; r1<r1+4; ++r1, ++i)
{
c[r1] = (char)i;
}

r1<r1+4 这是一定的,所以你这个循环是死循环。等r1大于c.length的时候就越界了。

[zx2002027]

public class Test {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
String s = "dcdabcddese";
char c[] = new char[s.length() + 1];
int i = 1;
int r1;

c = s.toCharArray();
r1 = s.indexOf("abcd");
int k=r1;
if (r1 != -1)
{
for (; r1<k+4; r1++, i++)
{
c[r1] = (char) ('0'+i);
}
}
System.out.print(c);

}

}
问题根源上面的都说完了